1. Field of the Invention
The present invention relates to an electronic stringed instrument, and, in particular, an electronic stringed instrument which can select a specific musical parameter, such as a timbre or a rhythm pattern by picking operation of strings.
2. Description of the Related Art
A known example of an electronic stringed instrument is a guitar synthesizer which is shaped like a guitar and has a synthesizer installed therein.
Guitar synthesizers can be classified into two types: the pickup type and the trigger type, on the basis of the system used for detecting a musical input entered by a player.
The pickup type synthesizer generally uses pickup sensors (typically, magnet type acoustic sensors) for independently detecting the vibrations of the individual strings. Since the output of each pickup sensor includes multifarious overtone or harmonic components in addition to a fundamental frequency component, this fundamental frequency component is therefore extracted from the sensor output by pitch extraction means. In addition, the timing at which string vibration starts and ends is detected by analyzing the level of the output of each pickup sensor.
When fundamental frequency data is extracted from the string vibration data and a condition to indicate the beginning of string vibration is met, a processor sends pitch data corresponding to the extracted fundamental frequency data to an internal or external sound source, so as to instruct generation of a musical tone of the associated string.
Then, when a condition for indicating the end of string vibration is satisfied, the processor instructs the sound source generating the musical tone to cease tone generation.
In contrast, the trigger type guitar synthesizer generally has a string trigger switch or a string trigger detector provided one for each string, for detecting the beginning of the string vibration, and has fret switches arranged in a fingerboard, for detecting the position operated on the fret with respect to each string. The fret switches can be an ON/OFF type arranged in a matrix on the fingerboard, a tablet coordination detection type, or a type in which conductive strings to be supplied with a minute current are stretched on the fingerboard and fret contacts are provided where each string is depressed.
When the beginning of a string vibration is detected through the string trigger switches or string trigger detectors, the processor reads out fret-operated position data (data attained through the fret switches) of a triggered string, prepares pitch data from the fret position data and the data of the string that has just started vibrating, and instructs an internal or external sound source to generate an associated tone. As a result, the sound source generates a tone having a specified pitch.
With either type of guitar synthesizer, a string-picking input entered by a player is utilized for no other purpose than to control the tone generated of the sound source and to control a short-duration parameter such as the pitch of the tone to be generated. However it is considered desirable that the player of the synthesizer be able to select other tone parameters (e.g., timbre) in addition to pitch. For instance, a guitar synthesizer having a communication function such as MIDI (Musical Instrument Digital Interface, which is the international standard for coupling musical instruments or mutual communication therebetween) generally has its communication line coupled to an external musical instrument or sound source module having a similar communicating function. With the use of such a guitar synthesizer, a timbre selection is likely to be executed while the synthesizer is being played. In such a case, the player or user should operate the timbre select switch provided on a panel of the external sound source module or the like to select the desired timbre of a tone to be generated. This necessitates that the user move to where a separated sound source module is located, every time the timbre change is needed. This is very troublesome to users. This may be solved by providing a timbre select switch on the main body of the guitar synthesizer; however, to ensure selection of a number of timbres (e.g., above 50 timbres), the same number of timbre select switches are required. Provision of many timbre select switches in the narrow guitar body not only increases the manufacturing cost of the synthesizer but also is difficult in consideration of the narrow space available in the guitar body.
The same problem would be raised in selecting other tone parameters, such as various rhythm patterns and various rhythms.
Recently, there has been proposed an electronic stringed instrument in which, with a specific function switch being depressed, for example, depressing the first fret of the first string changes the musical tone to a piano tone and depressing the second fret of the first string changes the musical tone to a string tone (as disclosed in the Japanese Patent Disclosure No. 62-47698). For instrument players, however, it is more natural and desirable to directly perform the picking of a string in order to select a musical tone with a specific timbre than to depress a specific fret position for the same purpose. If a timbre selection is performed by depressing a specific fret position, it is not easy for a player to sense what kind of timbre is actually selected.